The CNC controls are based around BeagleBone Black. I designed a CNC cape called OPTOCAPE. The design is documented and open source. You can buy an Optocape from my store on Tindie.
Optocape interfaces to most of the BeagleBone pins through Opto-isolated buffers. This allows the CPU, and machine signals to opperate from seperate power supplies.
Optocape also includes a built in LCD serializer. It is compatible with almost any laptop LCD flat panel. My machine uses a 14.1" sharp LQ141.
4-wire resistive touch is also supported. So Optocape is a good solution for any mid-sized machine requiring a touch screen.